The Key of David (3:7) maybe an important aspect of Philadelphia's success.
"I know your deeds. See, I have placed before you an open door that no one can shut. I know that you have little strength, yet you have kept my word and have not denied my name..." (3:8). Philadelphians loved God's Word and were intent on keeping it. They probably were an early personification of "The Body of Christ."
"I will make those who are of the synagogue of Satan, who claim to be Jews though they are not, but are liars -- I will make them come and fall down at your feet and acknowledge that I have loved you." (3:9). Evidently God granted the Christians in Philadelphia (the city of Brotherly Love) more power and influence over the false Jews than their brethren were able to muster in Smyrna.
"Since you have kept my command to endure patiently, I will also keep you from the hour of trial that is going to come upon the whole world to test those who live on the earth." (3:10). Smyrna suffers, but Philadelphia is kept from suffering -- even though both are faithful churches. God does not deal with everyone in the same way.
"Him who overcomes I will make a pillar in the temple of my God. Never again will he leave it. I will write on him the name of my God and the name of the city of my God, the new Jerusalem, which is coming down out of heaven from my God; and I will also write on him my new name." (3:12).*
*A pillar in the New Jerusalem? Is this the church (the type of people) that God will commission to build His New Jerusalem? Or, be given an influential role in the development of God's Holy City?
The name "Christian" was applied to the followers of Jesus Christ near the beginning of a new era that started approximately 2000 years ago. Will another new name be given to those who enter "the New Jerusalem?"